vfio: platform: No need to check res again

In function vfio_platform_regions_init(),we did check res implied
by using while loop,
so no need to check whether res be null or not again.

No functional change intended.
Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20230107034721.2127-1-angus.chen@jaguarmicro.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/platform/vfio_platform_common.c

@@ -150,9 +150,6 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
 		struct resource *res =
 			vdev->get_resource(vdev, i);
 
-		if (!res)
-			goto err;
-
 		vdev->regions[i].addr = res->start;
 		vdev->regions[i].size = resource_size(res);
 		vdev->regions[i].flags = 0;